diesel oils



DIESEL OILS J. RIEGERT ETAL Filed Nov. 14. 1960 March 10, 1964 E14. FDmPDO uzmvzm 2- uozdzo INVENTORS PATENT ATTORNEY United States Patent 3,124,433 DIESEL OHlS Jacques Riegert and Emmanuel Siganos, Notre-Dame-de- Gravenchon, France, assignors to Esso Research and Engineering Company, a corporation of Delaware Filed Nov. 14, 1960, Ser. No. 69,04 3 Claims. (Cl. 44-57) The present invention relates to an improved fuel oil and, more particularly, concerns liquid petroleum fuel 0118 having increased engine efiiciency and reduced tendency to produce exhaust smoke when utilized in internal combustion engines. This application is a continuationin-part of US. Serial No. 744,017, filed June 23, 1958, and now abandoned.

To increase the power output of an internal combustlon engine, for example, a diesel engine, it is common practice to inject a larger quantity of fuel into the combustion chamber. However, in the case of diesel engines when the quantity of injected fuel exceeds certain critical limits, then a copious liberation of smoke occurs in the exhaust gases due to incomplete combustion of the fuel. ThlS excessive exhaust smoke is particularly objectionable in diesel trucking operations. Further, the increased power output which is obtained as a result of the increased injection of fuel is not di ectly proportional to the amount of fuel used. Consequently, the specific consumption of the engine increases with increasing fuel in ection.

It has previously been proposed to add certain oil soluble lead salts to fuel oil, particularly diesel oils, to improve the anticorrosive properties of the oils. These lead salts have been constituted proknock additives, or, at the very least, are lead salts which do not adversely affect the ignition quality of the fuel as measured by cetane number. While these additives lessen the anticorrosive properties of fuel oils having high sulfur content, they have no effect on the combustion properties of the oil, particularly the tendency to cause smoke.

It has now been discovered that it is possible to substantially improve the properties of the fuel oil, particularly the tendency to smoke, by adding to the fuel oil a small proportion of the composition comprising a detergent and an organo-metallic compound.

The term organo-metallic compound is used to denote any compound in which the metal atom is directly linked to one or more carbon atoms belonging to a hydrocarbon radical.

Organic compounds of metals of groups II, IV, V, Vlb, or VIII of the periodic table may be used.

The preferred organo-metallic compounds are the compounds of metals of group IV of the periodic table, particularly lead. The especially preferred lead compounds are those lead alkyl compounds which are utilized as antiknoclc agents in gasoline compositions where they function as ignition suppressors in gasoline engines. It has been found that the novel use of a lead alkyl compound in combination with certain detergents produces the surprising result of a diminution in exhaust smoke and an increase in engine horsepower output. The utilization of a lead alkyl compound in a diesel fuel oil composition is an anomaly and contrary to normal diesel oil teachings. Lead alkyl compounds are known gasoline antiknock agents, and, normally, proknock additives are sought for diesel fuel compositions, or at the very least additives which do not adversely affect the cetane number of the diesel fuel. Thus, other lead salts having different organic constitutents have in the past been used in diesel fuels; but lead antiknock additives of the type described have been generally avoided, except in minute amounts, since they adversely affect the combustibility of diesel fuels. The applicants have found that the use of the alkyl lead gasoline antiknock agents in combination with certain detergents is surprisingly effective in decreasing exhaust smoke and increasing engine efficency. The lead alkyl compounds utilized in this invention include those oil soluble lead alkyl compounds and mixtures thereof, such as tetramethyl lead, tetraethyl lead, tetra-n-propyl lead, tetraisopropyl lead, tetrabutyl lead, methyl triethyl lead, dimethyl diethyl lead, tetraoctyl lead, and the like. The alkyl group may contain from 1 to 8 carbons atoms and can be straight or branch chained. The use of tetraethyl lead is preferred because of its superior performance qualities, commercial availability, and low cost.

The fuel oils to which the present invention is applicable are those liquid hydrocarbon fuel oils, and particularly those petroleum distillate fuels boiling above about 400 F. and including light fuel oils, gas oils used as fuel for diesel engines, heavy oils used in furnaces, kerosene diesel fuels, residual fuels, and the like. Suitable fuels are particularly set forth in ASTM tentative specifications, such as ASTM D-975-59T and ASTM D396 48T. The preferred fuel oils of the invention are those fuels used in diesel engines.

Any detergents may be used in the present invention in combination with the lead alkyl compounds. Polymeric or copolymeric products containing an active detergent group, which may be obtained by incorporating sulfurized or phosphosulfurized groups, or nitrogenor oxygen-containing groups, and which may or may not contain alkoxy groups, are suitable detergents.

Suitable detergents may be built up of copolymerizable unsaturated monoand/or dibasic acids, or alkoxy derivatives thereof, including ester derivatives. Such products may be derived from C to C alcohols and maleic and/or fumaric acids or mixtures of said esters including alkoxylated partial esters, and vinyl esters of C to C monobasic acids, e.g. vinyl acetate.

Other copolymeric compounds may be derived from alkyl-substituted acrylic acid and aliphatic alcohols, including amino alcohols.

Condensation products of an oil-soluble sulfonate and an alkyl polyamine, such as ethylene diamine and triethylamine, may be also used.

The preferred detergents of this invention when utilized with the lead alkyl compounds are those oil soluble metal sulfonates and particularly the oil soluble alkali and alkaline earth sulfonates. Those alkaline earth sulfonates derived from sulfonic acids which impart oil solubility to the compound are particularly suitable for the purposes of the invention.

The preferred metal sulfonates which can be used in this invention are the oil-soluble alkaline earth metal, e.g. barium calcium, salts of high molecular weight sulfonic acids, i.e. sulfonic acids, having a molecular weight of 200 to 800, e.g. 200 to 600. Such sulfonates may be derived by the treatment of petroleum oils of the lubricating oil range with fuming sulfuric acid as is well known to the art and as described in numerous patents, e.g.,

US. 2,467,176. The sulfonates can also be derived from relatively pure alkyl aryl sulfonic acids having from about to 33 carbon atoms per molecule. For example, sulfonated products of alkylated aromatics such as benzene, toluene, xylene, etc. alkylated with olefins or olefin polymers of the type of polypropylene, polyisobutylene, etc. can be used. Specific examples of sulfonates which are used as additives include: petroleum sulfonates such as calcium petroleum sulfonate and barium petroleum sulfonate; and synthetic sulffinates such as calcium di-C alkyl benzene sulfonate, barium di-Cg alkyl benzene sulfonate and calcium C alkyl benzene sulfonate, wherein said C alkyl group is derived from diisobutylene; said C group is obtained from tripropylene and said C group is obtained from tetraisobutylene. Suitable compounds include calcium sulfonate, barium sulfonate, sodium sulfonate, and the like.

Other preferred detergents are amines or the salts of an amine, and naphthenic or sulfonic acid, or any fatty acid. Particularly preferred are those alkanol amines, wherein the alkyl radical has less than 6 carbon atoms. Suitable alkanol amines include monomethanolamine, triethanolamine, ethanolarnine, trimethanolamine isopropanolamine, monobutanolamine, and the like.

A mixture of the above detergents may be used instead of any particular detergent.

The additive composition used in the present invention preferably comprises from 20 to 35% by weight of the said organometallic compounds and from 65 to 80% by Weight of the said detergent.

The total quantity of additive composition added to the fuel oil is preferably within the range of 0.001 to 0.2%, and more particularly 0.005 to 0.1% by weight of fuel oil.

The additive combinations of this invention are particularly effective in augmenting engine output at a smoke index of from 5.5 to 8.0 with maximum efliectiveness being observed from 6.0 to 7. 0.

Fuel oil compositions prepared according to the present invention were tested on a General Motors diesel engine (G.M. 371) having the following characteristics:

No. of cylinders 3.

Bore, mm 108 (4%"). Stroke, mm 127 (5"). Cylinder capacity, cc 3490 (212. cu. in). Temperature of water 80 C. Temperature of oil 107 C.

Speed 1200 r.p.m.

The smoke measurements at the exhaust were carried out with the smoke indicator known by the name of the Von Brand Smoke-Meter. This apparatus makes it possible to measure the smoke in the exhaust gases by causing them to pass through a paper screen which unwinds continuously at constant speed. The intensity of the spot obtained is measured by interpolation between two standards (one white, the other black); this determination is efiected by comparison with a datum scale, or more accurately, by measuring the percentage of light reflected by means of a photo-reflectometer.

EXAMPLE 1 The variation in the output of the said diesel engine Was studied as a function of the smoke index when the engine is fed with a fuel oil, with or without the additive compositions according to the present invention.

The gas oil used had the following characteristics:

Density at C 0.857 Viscosity, Engler at C 1.43 Sulfur, percent 0.5 Cetane number 42 The additive composition added to the above gas oil contained 40% by weight lead tetraethyl (TEL) and 60% by weight of various detergents and was added to the 4 gas oil in quantities such that 1 kilogram of gas oil contained 0.001'gram atoms of lead, i.e. 0.033% by weight of TEL and 0.050% by weight of the detergent.

The following results were obtained.

Variation 0 Engine Output in H .P. With Additive Combination TABLE I Smoke Gas Oil Gas Oil Gasfiil Gas Oil+ Expected A111 Index Alone +TEL +CS TgJ H.1E. Bonus See footnotes, Table II.

TABLE II Smoke Gas Oil Gas Oil Gas Oil Gas Oi1+ Expected AH.P Index Alone +TEL +TEA TEL+ H.P. Bonus TEA 5 1 Tetraethyl lead 0.33%.

2 Calcium sulfonate 0.050%.

3 Triethanolamine 0.050%.

4 0.033% TEL and 0.050% as.

I 0.033% TEL and 0.050% TEA.

The use of the novel additive combinations in diesel oil as demonstrated above produces exceptional increases in HP. as shown in Tables I and II. The above data show that the use of an alkyl lead gasoline antiknock agent in combination with a metal sulfonate and in combination with an alkanol amine, besides being a novel combination contrary to prior teachings, also produces surprising results in increasing engine horsepower. For example, in Table II, neither tetraethyl lead nor the amine separately increases engine horsepower; but in combination, the engine output is considerably enhanced. From the above examples, it can be seen that at a given smoke index the use of the additive combination increased the engine horsepower output. With the use of the additive combination, engine horsepower increased as much as 6 horsepower units.

The results of Table II have been graphically demonstrated in the drawing, wherein the change in engine output expressed as AH.P. from the base of the gas oil without any additives has been plotted against the smoke index. As can be seen, the additive combination of Table II is surprisingly effective.

EXAMPLE 2 The consumption of the said diesel engine at various outputs Was then determined using the gas oil alone and gas oil containing the additive compositions according to the present invention, as described in Example 1.

The following results were obtained:

Gas Oil Gas Oil Decrease Only Additive in Percent Output H1 H1.

Consumption in Liters Per Hour The results obtained in the above examples show that, by adding to the gas oil the additive compositions according to the present invention, for a given smoke index of 6, for example, there is a gain in output of from 12 to 15%, and that for a given output there is a decrease in consumption of from 1 to 2 /2 What is claimed is:

1. An improved fuel oil composition which reduces the tendency of the fuel oil to smoke, increases engine efiiciency, and reduces fuel consumption, said composition consisting essentially of a hydrocarbon fuel oil containing from, 0.001 to 0.2% by weight of an additive composition, consisting of from to by Weight of a lead alkyl compound, and from to by weight of an alkanolamine.

2. A composition as claimed in claim 1 wherein the said detergent is triethanolamine.

3. An improved diesel oil composition consisting essentially of a hydrocarbon fuel oil to which has been added from 0.005 to 0.1% by weight of an additive composition consisting of from 20 to 35% by weight of tetraethyl lead and from 65 to 80% by weight of triethanolamine.

References Cited in the file of this patent UNITED STATES PATENTS 2,141,848 Adams et al Dec. 27, 1938 2,151,432 Lyons et al Mar. 21, 1939 2,400,915 Campbell May 28, 1946 2,417,415 Hughes Mar. 18, 1947 2,560,542 Bartleson et al July 17, 1951 FOREIGN PATENTS 776,189 Great Britain June 5, 1957 OTHER REFERENCES Synthetic Organic Chemicals, Union Carbide and Carbon Chemicals Co., 13th edition, copyright 1952, pp. 91 and 92. 

1. AN IMPROVED FUEL OIL COMPOSITION WHICH REDUCES THE TENDENCY OF THE FUEL OIL TO SMOKE, INCREASES ENGINE EFFICIENCY, AND REDUCES FUEL CONSUMPTION, SAID COMPOSITION CONSISTING ESSENTIALLY OF A HYDROCARBON FUEL OIL CONTAINING FROM 0.001 TO 0.2% BY WEIGHT OF AN ADDITIVE COMPOSITION, CONSISTING OF FROM 20 TO 35% BY WEIGHT OF A LEAD ALKYL COMPOUND, AND FROM 65 TO 80% BY WEIGHT OF AN ALKANOLAMINE. 